"We're going to a party, disguised in fancy dress. But which of us is What or Who? It's up to you to guess!"Lift the flaps of this gloriously funny book to find out which animal is wearing which fancy dress costume. But when it comes to the last page, even the animals themselves are in for a surprise . . .'A dream team of writer and illustrator!' The Times 'The perfect pairing of Willis's rhyme and Ross's humourous illustration.' Good Book Guide